Merge 40fde52 into 61b46f8

config/decoder.go

@@ -29,6 +29,7 @@ import (
 	"strconv"
 
 	"github.com/go-validator/validator"
+	"github.com/pkg/errors"
 )
 
 type fieldInfo struct {
@@ -206,6 +207,10 @@ func addSeparator(key string) string {
 	return key
 }
 
+func addKeyToError(key string, err error) error {
+	return errors.Wrap(err, fmt.Sprintf("for key %q", key))
+}
+
 type decoder struct {
 	*Value
 	m map[interface{}]struct{}
@@ -236,12 +241,12 @@ func (d *decoder) scalar(childKey string, value reflect.Value, def string) error
 		// to convert to primitive,try converting the value as a struct value
 		if ret, err := convertValue(val, value.Type()); ret != nil {
 			if err != nil {
-				return err
+				return addKeyToError(childKey, err)
 			}
 
 			value.Set(reflect.ValueOf(ret))
 		} else {
-			return convertValueFromStruct(val, &value)
+			return addKeyToError(childKey, convertValueFromStruct(val, &value))
 		}
 	}
 
@@ -342,7 +347,8 @@ func (d *decoder) mapping(childKey string, value reflect.Value, def string) erro
 		for key := range v {
 			subKey := fmt.Sprintf("%v", key)
 			if subKey == "" {
-				return fmt.Errorf("empty key leads to ambiguity for path: %q", childKey)
+				// We can confuse an empty map key with a root element.
+				return addKeyToError(childKey, errors.New("empty map key is ambigious"))
 			}
 
 			itemValue := reflect.New(valueType.Elem()).Elem()
@@ -375,7 +381,7 @@ func (d *decoder) iface(key string, value reflect.Value, def string) error {
 		return nil
 	}
 
-	return fmt.Errorf("%q doesn't implement %q", src.Type(), value.Type())
+	return addKeyToError(key, fmt.Errorf("%q doesn't implement %q", src.Type(), value.Type()))
 }
 
 // Sets value to an object type.
@@ -426,7 +432,7 @@ func (d *decoder) valueStruct(key string, target interface{}) error {
 		}
 	}
 
-	return validator.Validate(target)
+	return addKeyToError(key, validator.Validate(target))
 }
 
 // If there is no value with name - leave it nil, otherwise allocate memory and set the value.
@@ -466,12 +472,12 @@ func (d *decoder) textUnmarshaller(key string, value reflect.Value, str string)
 
 	// Value has to have a pointer receiver to be able to modify itself with TextUnmarshaller
 	if !value.CanAddr() {
-		return fmt.Errorf("can't use TextUnmarshaller because %q is not addressable", key)
+		return addKeyToError(key, errors.New("can't use TextUnmarshaller because value is not addressable"))
 	}
 
 	switch t := value.Addr().Interface().(type) {
 	case encoding.TextUnmarshaler:
-		return t.UnmarshalText([]byte(str))
+		return addKeyToError(key, t.UnmarshalText([]byte(str)))
 	}
 
 	return nil
@@ -504,7 +510,7 @@ func (d *decoder) checkCycles(value reflect.Value) error {
 // Dispatch un-marshalling functions based on the value type.
 func (d *decoder) unmarshal(name string, value reflect.Value, def string) error {
 	if err := d.checkCycles(value); err != nil {
-		return err
+		return addKeyToError(name, err)
 	}
 
 	switch value.Kind() {

config/decoder_test.go

@@ -226,7 +226,7 @@ func TestUnsignedNumericDecodingNegatives(t *testing.T) {
 		t.Run(fmt.Sprintf("%q convert negative", to), func(t *testing.T) {
 			err := f(p)
 			require.Error(t, err)
-			assert.Contains(t, fmt.Sprintf("can't convert \"-1\" to unsigned integer type %q", to), err.Error())
+			assert.Contains(t, err.Error(), fmt.Sprintf("can't convert \"-1\" to unsigned integer type %q", to))
 		})
 	}
 }
@@ -542,3 +542,9 @@ func TestBoolParsing(t *testing.T) {
 	require.NoError(t, p.Get(Root).Populate(&alias))
 	assert.Equal(t, boolAlias(true), alias)
 }
+
+func TestAddKeyToErrorReturnsNilForNilErrors(t *testing.T) {
+	t.Parallel()
+
+	assert.NoError(t, addKeyToError("key", nil))
+}

config/static_provider_test.go

@@ -205,5 +205,6 @@ func TestPopulateForNestedMaps(t *testing.T) {
 	var m map[string]map[string]string
 	err := p.Get("a").Populate(&m)
 	require.Error(t, err)
-	assert.Contains(t, err.Error(), `empty key leads to ambiguity for path: "a."`)
+	assert.Contains(t, err.Error(), `empty map key is ambigious`)
+	assert.Contains(t, err.Error(), `a.`)
 }

config/yaml_test.go

@@ -439,7 +439,7 @@ func TestNilYAMLProviderSetDefaultTagValue(t *testing.T) {
 	}{}
 
 	p := NewYAMLProviderFromBytes(nil)
-	p.Get("hello").Populate(&data)
+	require.NoError(t, p.Get("hello").Populate(&data))
 
 	assert.Equal(t, 10, data.ID0)
 	assert.Equal(t, "string", data.ID1)
@@ -578,7 +578,10 @@ func TestLoops(t *testing.T) {
 	require.Equal(t, b, a)
 
 	p := testProvider{}
-	assert.Contains(t, p.Get(Root).Populate(&b).Error(), "cycles")
+	err := p.Get(Root).Populate(&b)
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "cycles")
+	assert.Contains(t, err.Error(), `for key "A.A"`)
 }
 
 func TestInternalFieldsAreNotSet(t *testing.T) {
@@ -730,7 +733,7 @@ func TestGrumpyUnmarshallerChannelFunction(t *testing.T) {
 		var r S
 		p := NewYAMLProviderFromBytes(src)
 		e := p.Get(Root).Populate(&r)
-		require.EqualError(t, e, message)
+		require.Contains(t, e.Error(), message)
 	}
 
 	chanError := []byte(`